1. Field of the Invention
The present invention relates to a joint assembly and particularly, but not exclusively, to a joint assembly for locking two components together, together with a method of using such a joint assembly.
2. Description of Related Art
It is known to use a wired joint to lock two cylindrical components to one another. Such an arrangement uses a wire having either a round (shown in FIG. 1) or square (shown in FIG. 2) cross section which is inserted into an annular cavity between the two components through a slot in the outer surface of the assembled components.
In order to ensure that the assembled components are held securely together, it is necessary for the wire to be a close fit in the annular cavity. The frictional forces resulting from this close fit make insertion, and particularly removal, of the wire difficult. This in turn renders this joint arrangement impractical for applications, such as gas turbine engines, where a cylindrical joint needs to be made and broken for maintenance and repair without having to apply undue force.
Most gas turbine engines employ conventional nut and bolt configurations to secure together the main structural engine components, such as fan and body casing parts. The temperature of gases passing through the engine can range between approximately 700° C. and approximately 2500° C. which can cause thermal cycling problems. As the engine temperature varies through such a temperature range, bolts tend to gall and seize. This can require the bolts to be drilled out during the disassembly of the engine, which is expensive and time-consuming. In addition, the use of nuts and bolts requires the use of corresponding flanges on the parts to be joined, which adds to weight and increases assembly time. Furthermore, in some arrangements, bolts heads are positioned in the gas flow path which may disrupt the aerodynamics of the engine and may accelerate the deterioration of the bolt.
The joint assembly of the present invention eliminates the requirement for a nut and bolt configuration and so reduces weight, speeds assembly and repair, minimises aerodynamic disruption in the flow path through the assembled components is simpler and less expensive than a conventional joint assembly, and reduces the high stress concentrations and bending loads associated with a bolted flanged joint.